This is what is missing from the federal investigation into Bridgegate:

The cell phone in Gov. Chris Christie's pocket during the 2013 George Washington lane closures.

Text messages the governor sent and received during the ensuing legislative investigation.

And now, according to new court filings, a personal email account he used as the scandal enveloped his administration.

None of this evidence was provided to federal criminal investigators probing the Bridgegate scandal, according to court documents.

For two and half years, Christie has insisted that both his personal and government email accounts were searched by investigators, and there was nothing to indicate he knew anything about the lane closures scheme.

But new court documents indicate that a personal email account he shared with his wife, Mary Pat, was never searched — and he used that account to send at least one Bridgegate-related email to David Samson, the chairman of the Port Authority of New York and New Jersey, which oversees the bridge. That email forwarded an article with the comment "per our earlier conversation" that discussed a phone conversation Christie had with New York Gov. Andrew Cuomo concerning the lane closure investigation.

Christie's own taxpayer-funded attorneys from the Gibson Dunn law firm, which has so far billed more than $10 million to the state, were in charge of responding to federal and legislative subpoenas seeking such emails. The lawyers simply ignored this account, even though Christie regularly used personal email accounts, including the one shared with his wife, for government business, sources say. He even used this account to email journalists concerning state business.

Two former Christie appointees indicted in the scheme are alleging that Gibson Dunn destroyed and withheld evidence. In defending itself, Gibson Dunn for the first time this week acknowledged that it never searched an email account where the sender was "Chris and Mary Pat Christie," until one of the defendants discovered the email to Samson earlier this month.

According to the legal papers that email was sent from a joint marital account of the Governor and his wife, "which we understood was not used by the Governor for official business and contained nothing responsive." Christie's lawyers say they've now searched that account and found no emails "related to and contemporaneous with the lane realignment."

The new admission runs contrary to what Christie said last year while campaigning in New Hampshire: "I turned over my email, both professional and personal, to all of the investigators who asked for them. And said, 'Look at whatever you want to look at.'"

This is all remarkably similar to the scandal that is dogging Hillary Clinton's presidential campaign — that she sent emails from a private server about government business that she failed to turn over to government lawyers. As a presidential candidate, Christie repeatedly slammed Clinton for this, saying he would "prosecute" her on a debate stage. Now presumptive Republican nominee Donald Trump is raising money off her email issue, asking for donations to "indict" her. Christie is a top adviser to the Trump campaign and is thought to be interested in a position in his administration.

The new revelations add to a growing list of questions about a possible Bridgegate cover-up. Among the missing evidence is Christie's cell phone, which the governor has said he turned over to investigators in 2014 after the scandal broke open with the "time for some traffic problems in Fort Lee" smoking gun email. He said he never saw the cell phone again, but federal investigators from the US Attorney's Office say they don't have it — and now, Christie's own attorneys refute his assertion.

Gibson Dunn told the court this week that the cell phone was reviewed to see if there was any evidence that needed to be provided in response to the U.S. Attorney's subpoena. The cell phone was then returned to the governor.

Also missing? Text messages that Christie sent to Regina Egea, his incoming chief-of-staff, who was attending a New Jersey Legislative hearing in December 2013 that was investigating what was still a mysterious lane closing and traffic jam. That day, top officials at the Port Authority refuted the claim made by Christie's appointee at the agency that the lane closures were caused by a traffic study. Christie's lawyers maintain in their brief that the texts were not relevant to the lane closures, even though Egea swore under oath she was texting the Governor concerning the lane closure investigation.

State taxpayers have spent more than $13 million on Christie's legal team and a digital forensics firm that scoured government electronic servers in the wake of the scandal, as of last August. WNYC's requests to obtain copies of the legal bills since August were first delayed by Gibson Dunn not having invoiced the state, and then by state officials who say they need more time to redact information in them. Lawyers were required to then turn over necessary digital evidence to federal prosecutors, but it now looks like the Bridgegate trial -- scheduled for September -- will center on how forthcoming the governor and his attorneys really were.

Matt Katz, New Jersey Public Radio/WNYC

Political reporter Matt Katz is The Christie Tracker at WNYC.org. NJ Spotlight is hosting his blog and running his stories, which can also be heard on WNYC 93.9 FM and 820 AM, as well as New Jersey Public Radio: Trenton 88.1, Sussex 88.5, Netcong 89.3, and Toms River 90.3.